Explain why a person's legs appear very short when wading in a pool. Justify your explanation with a ray diagram showing the path of rays from the feet to the eye of an observer who is out of the water.

A person's legs appear very short when wading in a pool due to the refraction of light as it travels from water to air. Refraction is the bending of light when it passes through different media with different speeds. In this situation, Snell's Law, which states that \(n_1\sin\theta_1 = n_2\sin\theta_2\), can be used to describe the relationship between the angles of incidence and refraction and the refractive indices of the two media. The ray diagram illustrating this phenomenon would show that light from the person's legs refracts away from the normal (a line perpendicular to the water's surface) when entering the air. Since the observer's brain does not account for this refraction, it traces the light rays back to an apparent position closer to the water's surface, making the legs appear shorter than they actually are.